The invention relates to a method and a circuit arrangement for the control of a motor, in particular a three-phase, three-strand motor which is coupled to an intermediate circuit voltage via a DC/AC converter which comprises DC/AC converter branches.
A method and a circuit arrangement for the control of a three-phase, three-strand motor are known from DE-OS 23 33 978. The three DC/AC converter branches of this known circuit arrangement each comprise two electronic switches with freewheel diodes connected in parallel thereto, while one electronic switch of each DC/AC converter branch is coupled to the positive intermediate circuit potential and the relevant other electronic switch is coupled to the negative intermediate circuit potential. In this known circuit arrangement, the sums of the currents of the electronic switches coupled to the negative intermediate circuit potential and the sums of the currents in the freewheel diodes connected in parallel thereto are measured and evaluated separately.
Such a separate measurement of the switch currents and freewheel diode currents, however, is possible to a limited degree only nowadays because most electronic switches comprise an integrated freewheel diode.